Tumblr Blocked in China but Ban Unlikely to Last

Tumblr is one of the few social media services that seems to escape being permanently banned in China.
It might go down for certain periods of time, but it always comes back
up again. This could be because Tumblr isn't as big and is instead
thought to be pretty harmless. However, some of the things that get posted on there go against what the Chinese government allow people to look at online.

Some people actually believe that users possibly speaking up about
the Chinese government are one of the reasons why Tumblr is being banned
at the moment. June 3-4 was when the Tiananmen Square massacre
occurred back in 1989 and China always more carefully monitors online
activity and social media during this period of time. It does then make
sense that Tumblr might be blocked as it is a social media service where
the government is likely to be condemned for their actions. However, when you look at June 3rd and 4th's statistics for the last few years, Tumblr wasn't blocked then.
There's been no plan of protests or memorials planned on Tumblr from
what I've heard so it seems as if it might be unrelated. Tumblr was also
blocked back in February and March 2011 after activists called for
social media users to protest against the Chinese government.

Tech Crunch

So far access to Tumblr has been limited since May 25th. The site was outright blocked on the 26th, 30th and the 2nd of June. We don't know how long this will go on for, but it seems unlikely that it will be blocked much longer. There have been periods of time like this in the past and then Tumblr users have been able to easily get back on.
It's hard to say how the Chinese government feel about Tumblr as this
could become a permanent thing but for now, users can have hope.

Other than Tiananmen Square, one of the reasons the Chinese government could have banned Tumblr, for now, is a sex tape that has apparently gone viral. The Chinese government have banned online pornography so this would make sense. Another possible reason is due to users accessing banned sites through VPN services though you do have to wonder how banning another site has anything to do with that.

Neither Tumblr nor the Chinese government has said anything on this so
it's just speculation until Tumblr either comes back online or goes down
over there forever.